نتایج جستجو برای: pear pollination
تعداد نتایج: 10801 فیلتر نتایج به سال:
Numerous studies have examined the evolution of sexual systems in angiosperms, but few explore the interaction between these and the evolution of pollination mode. Wind pollination is often associated with unisexual flowers, but which evolved first and played a causative role in the evolution of the other is unclear. Thalictrum, meadow-rues (Ranunculaceae), provides a unique opportunity to stud...
a principal obstacle facing intensive pear orchard establishment in iran is the absence of appropriate dwarfing or semi-dwarfing rootstocks, compatible with commercial cultivars, as well as showing adaptability with alkaline soils. this research aimed at an evaluation of the hawthorn seedlings (crataegus sp.) as a potential dwarfing rootstock for pear and a comparison of its dwarfing effects wi...
to investigate the effects of regulated deficit irrigation (rdi) on the growth, yield and quality of ‘yali’ pears, field experiments for c (fully watered control), ew [early withholding of irrigation, water stress from pullulation to 25 days after flower bloom (dafb)], mw (mid-growth withholding of irrigation, water stress from 25 dafb to 80 dafb), and lw (late withholding of irrigation, water ...
The ultimate causes of evolution of highly specialized pollination systems are little understood. We investigated the relationship between specialization and pollination efficiency, defined as the proportion of pollinated flowers relative to those that experienced pollen removal, using orchids with different pollination strategies as a model system. Rewarding orchids showed the highest pollinat...
Wind pollination is predominantly a derived condition in angiosperms and is thought to evolve in response to ecological conditions that render animal pollination less advantageous. However, the specific ecological and evolutionary mechanisms responsible for transitions from animal to wind pollination are poorly understood in comparison with other major reproductive transitions in angiosperms, i...
This study evaluated the effect of artificial pollination on pistachio trees in an orchard at a low ratio of male to female trees in Qazvin province, Iran, over the years 2012-2013. Experimental factors included three female cultivars (Akbari, Owhadi, Kalebozi) and three types of pollinizer (Control, GA, and GB) with three replications. In each female tree, two branches were selected in the nor...
orchard workers in north china are highly exposed to orchard pollens, especially peach and other rosaceae family pollens during pollination season. the aim of this study was to investigate whether occupational allergy to peach tree pollen as a member of rosaceae family is ige-mediated and to evaluate the cross-reactivity among rosaceae family pollens. allergen skin test and conjunctival challen...
Ecological restoration of plant-pollinator interactions has received surprisingly little attention, despite animal-mediated pollination underpinning reproduction of the majority of higher plants. Here, we offer a conceptual and practical framework for the ecological restoration of pollination mutualisms. Through the use of targeted restoration plantings to attract and sustain pollinators and in...
Pollination and fertilization of canola flowers are the main factors of canola seed production. In order to study the effects of insect pollinators on seed quantity and quality of three chosen cultivars of canola, namly, S.L.M., Okapi and Talaye, a split plot experiment in a complete randomized block design with four replications was carried out in Isfahan region. Main plots consisted of canola...
Nearly forty years ago R. L. Berg proposed that plants with specialized pollination ecology evolve genetic and developmental systems that decouple floral morphology from phenotypic variation in vegetative traits. These species evolve separate floral and vegetative trait clusters, or as she termed them, "correlation pleiades." The predictions of this hypothesis have been generally supported, but...
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